During the mating season the beak of the male Grey Heron changes from a yellow colour to a deep orange colour. The mating season is around February and flocks of Grey Herons can be seen on dancing grounds performing courtship dances.
When a female Grey Heron approaches a male, he starts to dance for her. He stretches his neck up to the sky and then bends it backwards until his head touches his back. While doing this the male keeps his beak pointing upwards all the time. If a male and female Grey Heron pair up for mating, they run and hop towards each other with their wings open. Then they change direction and run and hop towards each other again while snapping their beaks at each other.
Grey Herons like to build their nests high up in trees in woodland which is very close to water. Nests are often built close to other nests which creates a ‘loose’ nesting colony called a ‘heronry’. Some heronries may have up to a hundred nests. Both the male and the female Grey Heron like to build a nest together. The nest is usually quite shallow, bulky and saucer-shaped and is made out of small branches and twigs. It is lined with fresh grass and bracken. The female Grey Heron lays four to five greenish blue eggs around the end of March. Both the female and the male Heron incubate the eggs for approximately twenty-six days.
When the chicks hatch out, they are covered in long blackish-brown down feathers. The chicks are fed on regurgitated fish. After about twenty to thirty days, the chicks leave the nest and start to climb up and down branches. When they are approximately fifty days old, they get their first set of feathers necessary for flight and this is when they usually leave the heronry to find homes of their own.
Eventually when the young reach their second or third year, they too make have chicks of their own and so the cycle of life begins again.